/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* Copied from kernel/include/uapi/linux/btrfs_btree.h.
*
* Only modified the header.
*/
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef __BTRFS_TREE_H__
#define __BTRFS_TREE_H__
#include <linux/types.h>
#define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
/*
* The max metadata block size (node size).
*
* This limit is somewhat artificial. The memmove and tree block locking cost
* go up with larger node size.
*/
#define BTRFS_MAX_METADATA_BLOCKSIZE 65536
/*
* We can actually store much bigger names, but lets not confuse the rest
* of linux.
*
* btrfs_dir_item::name_len follows this limitation.
*/
#define BTRFS_NAME_LEN 255
/*
* Objectids start from here.
*
* Check btrfs_disk_key for the meaning of objectids.
*/
/*
* Root tree holds pointers to all of the tree roots.
* Without special mention, the root tree contains the root bytenr of all other
* trees, except the chunk tree and the log tree.
*
* The super block contains the root bytenr of this tree.
*/
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
/*
* Extent tree stores information about which extents are in use, and backrefs
* for each extent.
*/
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
/*
* Chunk tree stores btrfs logical address -> physical address mapping.
*
* The super block contains part of chunk tree for bootstrap, and contains
* the root bytenr of this tree.
*/
#define BTRFS_CHUNK_TREE_OBJECTID 3ULL
/*
* Device tree stores info about which areas of a given device are in use,
* and physical address -> btrfs logical address mapping.
*/
#define BTRFS_DEV_TREE_OBJECTID 4ULL
/* The fs tree is the first subvolume tree, storing files and directories. */
#define BTRFS_FS_TREE_OBJECTID 5ULL
/* Shows the directory objectid inside the root tree. */
#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
/* Csum tree holds checksums of all the data extents. */
#define BTRFS_CSUM_TREE_OBJECTID 7ULL
/* Quota tree holds quota configuration and tracking. */
#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
/* UUID tree stores items that use the BTRFS_UUID_KEY* types. */
#define BTRFS_UUID_TREE_OBJECTID 9ULL
/* Free space cache tree (v2 space cache) tracks free space in block groups. */
#define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
/* Indicates device stats in the device tree. */
#define BTRFS_DEV_STATS_OBJECTID 0ULL
/* For storing balance parameters in the root tree. */
#define BTRFS_BALANCE_OBJECTID -4ULL
/* Orhpan objectid for tracking unlinked/truncated files. */
#define BTRFS_ORPHAN_OBJECTID -5ULL
/* Does write ahead logging to speed up fsyncs. */
#define BTRFS_TREE_LOG_OBJECTID -6ULL
#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
/* For space balancing. */
#define BTRFS_TREE_RELOC_OBJECTID -8ULL
#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
/* Extent checksums, shared between the csum tree and log trees. */
#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
/* For storing free space cache (v1 space cache). */
#define BTRFS_FREE_SPACE_OBJECTID -11ULL
/* The inode number assigned to the special inode for storing free ino cache. */
#define BTRFS_FREE_INO_OBJECTID -12ULL
/* Dummy objectid represents multiple objectids. */
#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
/* All files have objectids in this range. */
#define BTRFS_FIRST_FREE_OBJECTID 256ULL
#define BTRFS_LAST_FREE_OBJECTID -256ULL
#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
/*
* The device items go into the chunk tree.
*
* The key is in the form
* (BTRFS_DEV_ITEMS_OBJECTID, BTRFS_DEV_ITEM_KEY, <device_id>)
*/
#define BTRFS_DEV_ITEMS_OBJECTID 1ULL
#define BTRFS_BTREE_INODE_OBJECTID 1
#define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
#define BTRFS_DEV_REPLACE_DEVID 0ULL
/*
* Types start from here.
*
* Check btrfs_disk_key for details about types.
*/
/*
* Inode items have the data typically returned from stat and store other
* info about object characteristics.
*
* There is one for every file and dir in the FS.
*/
#define BTRFS_INODE_ITEM_KEY 1
/* reserve 2-11 close to the inode for later flexibility */
#define BTRFS_INODE_REF_KEY 12
#define BTRFS_INODE_EXTREF_KEY 13
#define BTRFS_XATTR_ITEM_KEY 24
#define BTRFS_ORPHAN_ITEM_KEY 48
/*
* Dir items are the name -> inode pointers in a directory.
*
* There is one for every name in a directory.
*/
#define BTRFS_DIR_LOG_ITEM_KEY 60
#define BTRFS_DIR_LOG_INDEX_KEY 72
#define BTRFS_DIR_ITEM_KEY 84
#define BTRFS_DIR_INDEX_KEY 96
/* Stores info (position, size ...) about a data extent of a file */
#define BTRFS_EXTENT_DATA_KEY 108
/*
* Extent csums are stored in a separate tree and hold csums for
* an entire extent on disk.
*/
#define BTRFS_EXTENT_CSUM_KEY 128
/*
* Root items point to tree roots.
*
* They are typically in the root tree used by the super block to find all the
* other trees.
*/
#define BTRFS_ROOT_ITEM_KEY 132
/*
* Root backrefs tie subvols and snapshots to the directory entries that
* reference them.
*/
#define BTRFS_ROOT_BACKREF_KEY 144
/*
* Root refs make a fast index for listing all of the snapshots and
* subvolumes referenced by a given root. They point directly to the
* directory item in the root that references the subvol.
*/
#define BTRFS_ROOT_REF_KEY 156
/*
* Extent items are in the extent tree.
*
* These record which blocks are used, and how many references there are.
*/
#define BTRFS_EXTENT_ITEM_KEY 168
/*
* The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
* the length, so we save the level in key->offset instead of the length.
*/
#define BTRFS_METADATA_ITEM_KEY 169
#define BTRFS_TREE_BLOCK_REF_KEY 176
#define BTRFS_EXTENT_DATA_REF_KEY 178
#define BTRFS_EXTENT_REF_V0_KEY 180
#define BTRFS_SHARED_BLOCK_REF_KEY 182
#define BTRFS_SHARED_DATA_REF_KEY 184
/*
* Block groups give us hints into the extent allocation trees.
*
* Stores how many free space there is in a block group.
*/
#define BTRFS_BLOCK_GROUP_ITEM_KEY 192
/*
* Every block group is represented in the free space tree by a free space info
* item, which stores some accounting information. It is keyed on
* (block_group_start, FREE_SPACE_INFO, block_group_length).
*/
#define BTRFS_FREE_SPACE_INFO_KEY 198
/*
* A free space extent tracks an extent of space that is free in a block group.
* It is keyed on (start, FREE_SPACE_EXTENT, length).
*/
#define BTRFS_FREE_SPACE_EXTENT_KEY 199
/*
* When a block group becomes very fragmented, we convert it to use bitmaps
* instead of extents.
*
* A free space bitmap is keyed on (start, FREE_SPACE_BITMAP, length).
* The corresponding item is a bitmap with (length / sectorsize) bits.
*/
#define BTRFS_FREE_SPACE_BITMAP_KEY 200
#define BTRFS_DEV_EXTENT_KEY 204
#define BTRFS_DEV_ITEM_KEY 216
#define BTRFS_CHUNK_ITEM_KEY 228
/*
* Records the overall state of the qgroups.
*
* There's only one instance of this key present,
* (0, BTRFS_QGROUP_STATUS_KEY, 0)
*/
#define BTRFS_QGROUP_STATUS_KEY 240
/*
* Records the currently used space of the qgroup.
*
* One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
*/
#define BTRFS_QGROUP_INFO_KEY 242
/*
* Contains the user configured limits for the qgroup.
*
* One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
*/
#define BTRFS_QGROUP_LIMIT_KEY 244
/*
* Records the child-parent relationship of qgroups. For
* each relation, 2 keys are present:
* (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
* (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
*/
#define BTRFS_QGROUP_RELATION_KEY 246
/* Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY. */
#define BTRFS_BALANCE_ITEM_KEY 248
/*
* The key type for tree items that are stored persistently, but do not need to
* exist for extended period of time. The items can exist in any tree.
*
* [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
*
* Existing items:
*
* - balance status item
* (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
*/
#define BTRFS_TEMPORARY_ITEM_KEY 248
/* Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY */
#define BTRFS_DEV_STATS_KEY 249
/*
* The key type for tree items that are stored persistently and usually exist
* for a long period, eg. filesystem lifetime. The item kinds can be status
* information, stats or preference values. The item can exist in any tree.
*
* [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
*
* Existing items:
*
* - device statistics, store IO stats in the device tree, one key for all
* stats
* (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
*/
#define BTRFS_PERSISTENT_ITEM_KEY 249
/*
* Persistently stores the device replace state in the device tree.
*
* The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
*/
#define BTRFS_DEV_REPLACE_KEY 250
/*
* Stores items that allow to quickly map UUIDs to something else.
*
* These items are part of the filesystem UUID tree.
* The key is built like this:
* (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
*/
#define BTRFS_UUID_KEY_SUBVOL 251 /* for UUIDs assigned to subvols */
#define BTRFS_UUID_KEY_RECEIVED_SUBVOL 252 /* for UUIDs assigned to
* received subvols */
/*
* String items are for debugging.
*
* They just store a short string of data in the FS.
*/
#define BTRFS_STRING_ITEM_KEY 253
/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32
/* Csum types */
enum btrfs_csum_type {
BTRFS_CSUM_TYPE_CRC32 = 0,
BTRFS_CSUM_TYPE_XXHASH = 1,
BTRFS_CSUM_TYPE_SHA256 = 2,
BTRFS_CSUM_TYPE_BLAKE2 = 3,
};
/*
* Flags definitions for directory entry item type.
*
* Used by:
* struct btrfs_dir_item.type
*
* Values 0..7 must match common file type values in fs_types.h.
*/
#define BTRFS_FT_UNKNOWN 0
#define BTRFS_FT_REG_FILE 1
#define BTRFS_FT_DIR 2
#define BTRFS_FT_CHRDEV 3
#define BTRFS_FT_BLKDEV 4
#define BTRFS_FT_FIFO 5
#define BTRFS_FT_SOCK 6
#define BTRFS_FT_SYMLINK 7
#define BTRFS_FT_XATTR 8
#define BTRFS_FT_MAX 9
#define BTRFS_FSID_SIZE 16
#define BTRFS_UUID_SIZE 16
/*
* The key defines the order in the tree, and so it also defines (optimal)
* block layout.
*
* Objectid and offset are interpreted based on type.
* While normally for objectid, it either represents a root number, or an
* inode number.
*
* Type tells us things about the object, and is a kind of stream selector.
* Check the following URL for full references about btrfs_disk_key/btrfs_key:
* https://btrfs.wiki.kernel.org/index.php/Btree_Items
*
* btrfs_disk_key is in disk byte order. struct btrfs_key is always
* in cpu native order. Otherwise they are identical and their sizes
* should be the same (ie both packed)
*/
struct btrfs_disk_key {
__le64 objectid;
__u8 type;
__le64 offset;
} __attribute__ ((__packed__));
struct btrfs_key {
__u64 objectid;
__u8 type;
__u64 offset;
} __attribute__ ((__packed__));
struct btrfs_dev_item {
/* The internal btrfs device id */
__le64 devid;
/* Size of the device */
__le64 total_bytes;
/* Bytes used */
__le64 bytes_used;
/* Optimal io alignment for this device */
__le32 io_align;
/* Optimal io width for this device */
__le32 io_width;
/* Minimal io size for this device */
__le32 sector_size;
/* Type and info about this device */
__le64 type;
/* Expected generation for this device */
__le64 generation;
/*
* Starting byte of this partition on the device,
* to allow for stripe alignment in the future.
*/
__le64 start_offset;
/* Grouping information for allocation decisions */
__le32 dev_group;
/* Optimal seek speed 0-100 where 100 is fastest */
__u8 seek_speed;
/* Optimal bandwidth 0-100 where 100 is fastest */
__u8 bandwidth;
/* Btrfs generated uuid for this device */
__u8 uuid[BTRFS_UUID_SIZE];
/* UUID of FS who owns this device */
__u8 fsid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));
struct btrfs_stripe {
__le64 devid;
__le64 offset;
__u8 dev_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));
struct btrfs_chunk {
/* Size of this chunk in bytes */
__le64 length;
/* Objectid of the root referencing this chunk */
__le64 owner;
__le64 stripe_len;
__le64 type;
/* Optimal io alignment for this chunk */
__le32 io_align;
/* Optimal io width for this chunk */
__le32 io_width;
/* Minimal io size for this chunk */
__le32 sector_size;
/*
* 2^16 stripes is quite a lot, a second limit is the size of a single
* item in the btree.
*/
__le16 num_stripes;
/* Sub stripes only matter for raid10 */
__le16 sub_stripes;
struct btrfs_stripe stripe;
/* additional stripes go here */
} __attribute__ ((__packed__));
#define BTRFS_FREE_SPACE_EXTENT 1
#define BTRFS_FREE_SPACE_BITMAP 2
struct btrfs_free_space_entry {
__le64 offset;
__le64 bytes;
__u8 type;
} __attribute__ ((__packed__));
struct btrfs_free_space_header {
struct btrfs_disk_key location;
__le64 generation;
__le64 num_entries;
__le64 num_bitmaps;
} __attribute__ ((__packed__));
#define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0)
#define BTRFS_HEADER_FLAG_RELOC (1ULL << 1)
/* Super block flags */
/* Errors detected */
#define BTRFS_SUPER_FLAG_ERROR (1ULL << 2)
#define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32)
#define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33)
#define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34)
#define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35)
#define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36)
/*
* Items in the extent tree are used to record the objectid of the
* owner of the block and the number of references.
*/
struct btrfs_extent_item {
__le64 refs;
__le64 generation;
__le64 flags;
} __attribute__ ((__packed__));
struct btrfs_extent_item_v0 {
__le32 refs;
} __attribute__ ((__packed__));
#define BTRFS_EXTENT_FLAG_DATA (1ULL << 0)
#define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1)
/* Use full backrefs for extent pointers in the block */
#define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8)
/*
* This flag is only used internally by scrub and may be changed at any time
* it is only declared here to avoid collisions.
*/
#define BTRFS_EXTENT_FLAG_SUPER (1ULL << 48)
struct btrfs_tree_block_info {
struct btrfs_disk_key key;
__u8 level;
} __attribute__ ((__packed__));
struct btrfs_extent_data_ref {
__le64 root;
__le64 objectid;
__le64 offset;
__le32 count;
} __attribute__ ((__packed__));
struct btrfs_shared_data_ref {
__le32 count;
} __attribute__ ((__packed__));
struct btrfs_extent_inline_ref {
__u8 type;
__le64 offset;
} __attribute__ ((__packed__));
/* Old style backrefs item */
struct btrfs_extent_ref_v0 {
__le64 root;
__le64 generation;
__le64 objectid;
__le32 count;
} __attribute__ ((__packed__));
/* Dev extents record used space on individual devices.
*
* The owner field points back to the chunk allocation mapping tree that
* allocated the extent.
* The chunk tree uuid field is a way to double check the owner.
*/
struct btrfs_dev_extent {
__le64 chunk_tree;
__le64 chunk_objectid;
__le64 chunk_offset;
__le64 length;
__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));
struct btrfs_inode_ref {
__le64 index;
__le16 name_len;
/* Name goes here */
} __attribute__ ((__packed__));
struct btrfs_inode_extref {
__le64 parent_objectid;
__le64 index;
__le16 name_len;
__u8 name[0];
/* Name goes here */
} __attribute__ ((__packed__));
struct btrfs_timespec {
__le64 sec;
__le32 nsec;
} __attribute__ ((__packed__));
/* Inode flags */
#define BTRFS_INODE_NODATASUM (1 << 0)
#define BTRFS_INODE_NODATACOW (1 << 1)
#define BTRFS_INODE_READONLY (1 << 2)
#define BTRFS_INODE_NOCOMPRESS (1 << 3)
#define BTRFS_INODE_PREALLOC (1 << 4)
#define BTRFS_INODE_SYNC (1 << 5)
#define BTRFS_INODE_IMMUTABLE (1 << 6)
#define BTRFS_INODE_APPEND (1 << 7)
#define BTRFS_INODE_NODUMP (1 << 8)
#define BTRFS_INODE_NOATIME (1 << 9)
#define BTRFS_INODE_DIRSYNC (1 << 10)
#define BTRFS_INODE_COMPRESS (1 << 11)
#define BTRFS_INODE_ROOT_ITEM_INIT (1 << 31)
#define BTRFS_INODE_FLAG_MASK \
(BTRFS_INODE_NODATASUM | \
BTRFS_INODE_NODATACOW | \
BTRFS_INODE_READONLY | \
BTRFS_INODE_NOCOMPRESS | \
BTRFS_INODE_PREALLOC | \
BTRFS_INODE_SYNC | \
BTRFS_INODE_IMMUTABLE | \
BTRFS_INODE_APPEND | \
BTRFS_INODE_NODUMP | \
BTRFS_INODE_NOATIME | \
BTRFS_INODE_DIRSYNC | \
BTRFS_INODE_COMPRESS | \
BTRFS_INODE_ROOT_ITEM_INIT)
struct btrfs_inode_item {
/* Nfs style generation number */
__le64 generation;
/* Transid that last touched this inode */
__le64 transid;
__le64 size;
__le64 nbytes;
__le64 block_group;
__le32 nlink;
__le32 uid;
__le32 gid;
__le32 mode;
__le64 rdev;
__le64 flags;
/* Modification sequence number for NFS */
__le64 sequence;
/*
* A little future expansion, for more than this we can just grow the
* inode item and version it
*/
__le64 reserved[4];
struct btrfs_timespec atime;
struct btrfs_timespec ctime;
struct btrfs_timespec mtime;
struct btrfs_timespec otime;
} __attribute__ ((__packed__));
struct btrfs_dir_log_item {
__le64 end;
} __attribute__ ((__packed__));
struct btrfs_dir_item {
struct btrfs_disk_key location;
__le64 transid;
__le16 data_len;
__le16 name_len;
__u8 type;
} __attribute__ ((__packed__));
#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
/*
* Internal in-memory flag that a subvolume has been marked for deletion but
* still visible as a directory
*/
#define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48)
struct btrfs_root_item {
struct btrfs_inode_item inode;
__le64 generation;
__le64 root_dirid;
__le64 bytenr;
__le64 byte_limit;
__le64 bytes_used;
__le64 last_snapshot;
__le64 flags;
__le32 refs;
struct btrfs_disk_key drop_progress;
__u8 drop_level;
__u8 level;
/*
* The following fields appear after subvol_uuids+subvol_times
* were introduced.
*/
/*
* This generation number is used to test if the new fields are valid
* and up to date while reading the root item. Every time the root item
* is written out, the "generation" field is copied into this field. If
* anyone ever mounted the fs with an older kernel, we will have
* mismatching generation values here and thus must invalidate the
* new fields. See btrfs_update_root and btrfs_find_last_root for
* details.
* The offset of generation_v2 is also used as the start for the memset
* when invalidating the fields.
*/
__le64 generation_v2;
__u8 uuid[BTRFS_UUID_SIZE];
__u8 parent_uuid[BTRFS_UUID_SIZE];
__u8 received_uuid[BTRFS_UUID_SIZE];
__le64 ctransid; /* Updated when an inode changes */
__le64 otransid; /* Trans when created */
__le64 stransid; /* Trans when sent. Non-zero for received subvol. */
__le64 rtransid; /* Trans when received. Non-zero for received subvol.*/
struct btrfs_timespec ctime;
struct btrfs_timespec otime;
struct btrfs_timespec stime;
struct btrfs_timespec rtime;
__le64 reserved[8]; /* For future */
} __attribute__ ((__packed__));
/* This is used for both forward and backward root refs */
struct btrfs_root_ref {
__le64 dirid;
__le64 sequence;
__le16 name_len;
} __attribute__ ((__packed__));
struct btrfs_disk_balance_args {
/*
* Profiles to operate on.
*
* SINGLE is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE.
*/
__le64 profiles;
/*
* Usage filter
* BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
* BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
*/
union {
__le64 usage;
struct {
__le32 usage_min;
__le32 usage_max;
};
};
/* Devid filter */
__le64 devid;
/* Devid subset filter [pstart..pend) */
__le64 pstart;
__le64 pend;
/* Btrfs virtual address space subset filter [vstart..vend) */
__le64 vstart;
__le64 vend;
/*
* Profile to convert to.
*
* SINGLE is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE.
*/
__le64 target;
/* BTRFS_BALANCE_ARGS_* */
__le64 flags;
/*
* BTRFS_BALANCE_ARGS_LIMIT with value 'limit'.
* BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
* and maximum.
*/
union {
__le64 limit;
struct {
__le32 limit_min;
__le32 limit_max;
};
};
/*
* Process chunks that cross stripes_min..stripes_max devices,
* BTRFS_BALANCE_ARGS_STRIPES_RANGE.
*/
__le32 stripes_min;
__le32 stripes_max;
__le64 unused[6];
} __attribute__ ((__packed__));
/*
* Stores balance parameters to disk so that balance can be properly
* resumed after crash or unmount.
*/
struct btrfs_balance_item {
/* BTRFS_BALANCE_* */
__le64 flags;
struct btrfs_disk_balance_args data;
struct btrfs_disk_balance_args meta;
struct btrfs_disk_balance_args sys;
__le64 unused[4];
} __attribute__ ((__packed__));
enum {
BTRFS_FILE_EXTENT_INLINE = 0,
BTRFS_FILE_EXTENT_REG = 1,
BTRFS_FILE_EXTENT_PREALLOC = 2,
BTRFS_NR_FILE_EXTENT_TYPES = 3,
};
enum btrfs_compression_type {
BTRFS_COMPRESS_NONE = 0,
BTRFS_COMPRESS_ZLIB = 1,
BTRFS_COMPRESS_LZO = 2,
BTRFS_COMPRESS_ZSTD = 3,
BTRFS_NR_COMPRESS_TYPES = 4,
};
struct btrfs_file_extent_item {
/* Transaction id that created this extent */
__le64 generation;
/*
* Max number of bytes to hold this extent in ram.
*
* When we split a compressed extent we can't know how big each of the
* resulting pieces will be. So, this is an upper limit on the size of
* the extent in ram instead of an exact limit.
*/
__le64 ram_bytes;
/*
* 32 bits for the various ways we might encode the data,
* including compression and encryption. If any of these
* are set to something a given disk format doesn't understand
* it is treated like an incompat flag for reading and writing,
* but not for stat.
*/
__u8 compression;
__u8 encryption;
__le16 other_encoding; /* Spare for later use */
/* Are we inline data or a real extent? */
__u8 type;
/*
* Disk space consumed by the extent, checksum blocks are not included
* in these numbers
*
* At this offset in the structure, the inline extent data start.
*/
__le64 disk_bytenr;
__le64 disk_num_bytes;
/*
* The logical offset inside the file extent.
*
* This allows a file extent to point into the middle of an existing
* extent on disk, sharing it between two snapshots (useful if some
* bytes in the middle of the extent have changed).
*/
__le64 offset;
/*
* The logical number of bytes this file extent is referencing (no
* csums included).
*
* This always reflects the size uncompressed and without encoding.
*/
__le64 num_bytes;
} __attribute__ ((__packed__));
struct btrfs_csum_item {
__u8 csum;
} __attribute__ ((__packed__));
enum btrfs_dev_stat_values {
/* Disk I/O failure stats */
BTRFS_DEV_STAT_WRITE_ERRS, /* EIO or EREMOTEIO from lower layers */
BTRFS_DEV_STAT_READ_ERRS, /* EIO or EREMOTEIO from lower layers */
BTRFS_DEV_STAT_FLUSH_ERRS, /* EIO or EREMOTEIO from lower layers */
/* Stats for indirect indications for I/O failures */
BTRFS_DEV_STAT_CORRUPTION_ERRS, /* Checksum error, bytenr error or
* contents is illegal: this is an
* indication that the block was damaged
* during read or write, or written to
* wrong location or read from wrong
* location */
BTRFS_DEV_STAT_GENERATION_ERRS, /* An indication that blocks have not
* been written */
BTRFS_DEV_STAT_VALUES_MAX
};
struct btrfs_dev_stats_item {
/*
* Grow this item struct at the end for future enhancements and keep
* the existing values unchanged.
*/
__le64 values[BTRFS_DEV_STAT_VALUES_MAX];
} __attribute__ ((__packed__));
#define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0
#define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1
struct btrfs_dev_replace_item {
/*
* Grow this item struct at the end for future enhancements and keep
* the existing values unchanged.
*/
__le64 src_devid;
__le64 cursor_left;
__le64 cursor_right;
__le64 cont_reading_from_srcdev_mode;
__le64 replace_state;
__le64 time_started;
__le64 time_stopped;
__le64 num_write_errors;
__le64 num_uncorrectable_read_errors;
} __attribute__ ((__packed__));
/* Different types of block groups (and chunks) */
#define BTRFS_BLOCK_GROUP_DATA (1ULL << 0)
#define BTRFS_BLOCK_GROUP_SYSTEM (1ULL << 1)
#define BTRFS_BLOCK_GROUP_METADATA (1ULL << 2)
#define BTRFS_BLOCK_GROUP_RAID0 (1ULL << 3)
#define BTRFS_BLOCK_GROUP_RAID1 (1ULL << 4)
#define BTRFS_BLOCK_GROUP_DUP (1ULL << 5)
#define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6)
#define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7)
#define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8)
#define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9)
#define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10)
#define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
BTRFS_SPACE_INFO_GLOBAL_RSV)
enum btrfs_raid_types {
BTRFS_RAID_RAID10,
BTRFS_RAID_RAID1,
BTRFS_RAID_DUP,
BTRFS_RAID_RAID0,
BTRFS_RAID_SINGLE,
BTRFS_RAID_RAID5,
BTRFS_RAID_RAID6,
BTRFS_RAID_RAID1C3,
BTRFS_RAID_RAID1C4,
BTRFS_NR_RAID_TYPES
};
#define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \
BTRFS_BLOCK_GROUP_SYSTEM | \
BTRFS_BLOCK_GROUP_METADATA)
#define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \
BTRFS_BLOCK_GROUP_RAID1 | \
BTRFS_BLOCK_GROUP_RAID1C3 | \
BTRFS_BLOCK_GROUP_RAID1C4 | \
BTRFS_BLOCK_GROUP_RAID5 | \
BTRFS_BLOCK_GROUP_RAID6 | \
BTRFS_BLOCK_GROUP_DUP | \
BTRFS_BLOCK_GROUP_RAID10)
#define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \
BTRFS_BLOCK_GROUP_RAID6)
#define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \
BTRFS_BLOCK_GROUP_RAID1C3 | \
BTRFS_BLOCK_GROUP_RAID1C4)
/*
* We need a bit for restriper to be able to tell when chunks of type
* SINGLE are available. This "extended" profile format is used in
* fs_info->avail_*_alloc_bits (in-memory) and balance item fields
* (on-disk). The corresponding on-disk bit in chunk.type is reserved
* to avoid remappings between two formats in future.
*/
#define BTRFS_AVAIL_ALLOC_BIT_SINGLE (1ULL << 48)
/*
* A fake block group type that is used to communicate global block reserve
* size to userspace via the SPACE_INFO ioctl.
*/
#define BTRFS_SPACE_INFO_GLOBAL_RSV (1ULL << 49)
#define BTRFS_EXTENDED_PROFILE_MASK (BTRFS_BLOCK_GROUP_PROFILE_MASK | \
BTRFS_AVAIL_ALLOC_BIT_SINGLE)
static inline __u64 chunk_to_extended(__u64 flags)
{
if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0)
flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE;
return flags;
}
static inline __u64 extended_to_chunk(__u64 flags)
{
return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
}
struct btrfs_block_group_item {
__le64 used;
__le64 chunk_objectid;
__le64 flags;
} __attribute__ ((__packed__));
struct btrfs_free_space_info {
__le32 extent_count;
__le32 flags;
} __attribute__ ((__packed__));
#define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0)
#define BTRFS_QGROUP_LEVEL_SHIFT 48
static inline __u64 btrfs_qgroup_level(__u64 qgroupid)
{
return qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT;
}
/* Is subvolume quota turned on? */
#define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0)
/* Is qgroup rescan running? */
#define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1)
/*
* Some qgroup entries are known to be out of date, either because the
* configuration has changed in a way that makes a rescan necessary, or
* because the fs has been mounted with a non-qgroup-aware version.
*/
#define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2)
#define BTRFS_QGROUP_STATUS_VERSION 1
struct btrfs_qgroup_status_item {
__le64 version;
/*
* The generation is updated during every commit. As older
* versions of btrfs are not aware of qgroups, it will be
* possible to detect inconsistencies by checking the
* generation on mount time.
*/
__le64 generation;
/* Flag definitions see above */
__le64 flags;
/*
* Only used during scanning to record the progress of the scan.
* It contains a logical address.
*/
__le64 rescan;
} __attribute__ ((__packed__));
struct btrfs_qgroup_info_item {
__le64 generation;
__le64 rfer;
__le64 rfer_cmpr;
__le64 excl;
__le64 excl_cmpr;
} __attribute__ ((__packed__));
/*
* Flags definition for qgroup limits
*
* Used by:
* struct btrfs_qgroup_limit.flags
* struct btrfs_qgroup_limit_item.flags
*/
#define BTRFS_QGROUP_LIMIT_MAX_RFER (1ULL << 0)
#define BTRFS_QGROUP_LIMIT_MAX_EXCL (1ULL << 1)
#define BTRFS_QGROUP_LIMIT_RSV_RFER (1ULL << 2)
#define BTRFS_QGROUP_LIMIT_RSV_EXCL (1ULL << 3)
#define BTRFS_QGROUP_LIMIT_RFER_CMPR (1ULL << 4)
#define BTRFS_QGROUP_LIMIT_EXCL_CMPR (1ULL << 5)
struct btrfs_qgroup_limit_item {
/* Only updated when any of the other values change. */
__le64 flags;
__le64 max_rfer;
__le64 max_excl;
__le64 rsv_rfer;
__le64 rsv_excl;
} __attribute__ ((__packed__));
/*
* Just in case we somehow lose the roots and are not able to mount,
* we store an array of the roots from previous transactions in the super.
*/
#define BTRFS_NUM_BACKUP_ROOTS 4
struct btrfs_root_backup {
__le64 tree_root;
__le64 tree_root_gen;
__le64 chunk_root;
__le64 chunk_root_gen;
__le64 extent_root;
__le64 extent_root_gen;
__le64 fs_root;
__le64 fs_root_gen;
__le64 dev_root;
__le64 dev_root_gen;
__le64 csum_root;
__le64 csum_root_gen;
__le64 total_bytes;
__le64 bytes_used;
__le64 num_devices;
/* future */
__le64 unused_64[4];
u8 tree_root_level;
u8 chunk_root_level;
u8 extent_root_level;
u8 fs_root_level;
u8 dev_root_level;
u8 csum_root_level;
/* future and to align */
u8 unused_8[10];
} __attribute__ ((__packed__));
/*
* This is a very generous portion of the super block, giving us room to
* translate 14 chunks with 3 stripes each.
*/
#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
#define BTRFS_LABEL_SIZE 256
/* The super block basically lists the main trees of the FS. */
struct btrfs_super_block {
/* The first 4 fields must match struct btrfs_header */
u8 csum[BTRFS_CSUM_SIZE];
/* FS specific UUID, visible to user */
u8 fsid[BTRFS_FSID_SIZE];
__le64 bytenr; /* this block number */
__le64 flags;
/* Allowed to be different from the btrfs_header from here own down. */
__le64 magic;
__le64 generation;
__le64 root;
__le64 chunk_root;
__le64 log_root;
/* This will help find the new super based on the log root. */
__le64 log_root_transid;
__le64 total_bytes;
__le64 bytes_used;
__le64 root_dir_objectid;
__le64 num_devices;
__le32 sectorsize;
__le32 nodesize;
__le32 __unused_leafsize;
__le32 stripesize;
__le32 sys_chunk_array_size;
__le64 chunk_root_generation;
__le64 compat_flags;
__le64 compat_ro_flags;
__le64 incompat_flags;
__le16 csum_type;
u8 root_level;
u8 chunk_root_level;
u8 log_root_level;
struct btrfs_dev_item dev_item;
char label[BTRFS_LABEL_SIZE];
__le64 cache_generation;
__le64 uuid_tree_generation;
/* The UUID written into btree blocks */
u8 metadata_uuid[BTRFS_FSID_SIZE];
/* Future expansion */
__le64 reserved[28];
u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
} __attribute__ ((__packed__));
/*
* Feature flags
*
* Used by:
* struct btrfs_super_block::(compat|compat_ro|incompat)_flags
* struct btrfs_ioctl_feature_flags
*/
#define BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE (1ULL << 0)
/*
* Older kernels (< 4.9) on big-endian systems produced broken free space tree
* bitmaps, and btrfs-progs also used to corrupt the free space tree (versions
* < 4.7.3). If this bit is clear, then the free space tree cannot be trusted.
* btrfs-progs can also intentionally clear this bit to ask the kernel to
* rebuild the free space tree, however this might not work on older kernels
* that do not know about this bit. If not sure, clear the cache manually on
* first mount when booting older kernel versions.
*/
#define BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID (1ULL << 1)
#define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0)
#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1)
#define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2)
#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3)
#define BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD (1ULL << 4)
/*
* Older kernels tried to do bigger metadata blocks, but the
* code was pretty buggy. Lets not let them try anymore.
*/
#define BTRFS_FEATURE_INCOMPAT_BIG_METADATA (1ULL << 5)
#define BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF (1ULL << 6)
#define BTRFS_FEATURE_INCOMPAT_RAID56 (1ULL << 7)
#define BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA (1ULL << 8)
#define BTRFS_FEATURE_INCOMPAT_NO_HOLES (1ULL << 9)
#define BTRFS_FEATURE_INCOMPAT_METADATA_UUID (1ULL << 10)
#define BTRFS_FEATURE_INCOMPAT_RAID1C34 (1ULL << 11)
/*
* Compat flags that we support.
*
* If any incompat flags are set other than the ones specified below then we
* will fail to mount.
*/
#define BTRFS_FEATURE_COMPAT_SUPP 0ULL
#define BTRFS_FEATURE_COMPAT_SAFE_SET 0ULL
#define BTRFS_FEATURE_COMPAT_SAFE_CLEAR 0ULL
#define BTRFS_FEATURE_COMPAT_RO_SUPP \
(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE | \
BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID)
#define BTRFS_FEATURE_COMPAT_RO_SAFE_SET 0ULL
#define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR 0ULL
#define BTRFS_FEATURE_INCOMPAT_SUPP \
(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \
BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \
BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \
BTRFS_FEATURE_INCOMPAT_BIG_METADATA | \
BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO | \
BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD | \
BTRFS_FEATURE_INCOMPAT_RAID56 | \
BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF | \
BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA | \
BTRFS_FEATURE_INCOMPAT_NO_HOLES | \
BTRFS_FEATURE_INCOMPAT_METADATA_UUID | \
BTRFS_FEATURE_INCOMPAT_RAID1C34)
#define BTRFS_FEATURE_INCOMPAT_SAFE_SET \
(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
#define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR 0ULL
#define BTRFS_BACKREF_REV_MAX 256
#define BTRFS_BACKREF_REV_SHIFT 56
#define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \
BTRFS_BACKREF_REV_SHIFT)
#define BTRFS_OLD_BACKREF_REV 0
#define BTRFS_MIXED_BACKREF_REV 1
#define BTRFS_MAX_LEVEL 8
/* Every tree block (leaf or node) starts with this header. */
struct btrfs_header {
/* These first four must match the super block */
u8 csum[BTRFS_CSUM_SIZE];
u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
__le64 bytenr; /* Which block this node is supposed to live in */
__le64 flags;
/* Allowed to be different from the super from here on down. */
u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
__le64 generation;
__le64 owner;
__le32 nritems;
u8 level;
} __attribute__ ((__packed__));
/*
* A leaf is full of items. Offset and size tell us where to find
* the item in the leaf (relative to the start of the data area).
*/
struct btrfs_item {
struct btrfs_disk_key key;
__le32 offset;
__le32 size;
} __attribute__ ((__packed__));
/*
* leaves have an item area and a data area:
* [item0, item1....itemN] [free space] [dataN...data1, data0]
*
* The data is separate from the items to get the keys closer together
* during searches.
*/
struct btrfs_leaf {
struct btrfs_header header;
struct btrfs_item items[];
} __attribute__ ((__packed__));
/*
* All non-leaf blocks are nodes, they hold only keys and pointers to children
* blocks.
*/
struct btrfs_key_ptr {
struct btrfs_disk_key key;
__le64 blockptr;
__le64 generation;
} __attribute__ ((__packed__));
struct btrfs_node {
struct btrfs_header header;
struct btrfs_key_ptr ptrs[];
} __attribute__ ((__packed__));
#endif /* __BTRFS_TREE_H__ */